He is literally the sprout of the idea of a ruler of hell, so he's naturally extraordinarily powerful, He holds no mercy, so if he needs something done he will not stop until everything stopping him from acomplishing that goal is completely obliterated, A few of his powers are:

Thundering Blast: A black ball of thundering electricity which deals better damage to Machine type digimon, but slightly less to other types, It can be charged fully to destroy large chunks of everything.

Black Wall: A wall of shadows emerges from... well.. the dark! If no darkness is able to summon the wall, then it simply emerges from the darkness inside the dirt or current ground.

Eye in the Dark: An eye emerges from a Black Wall, Chenihauritismon can see through it clearly.

He's literally the Grim Reaper, pretty much Death itself, and is displayed as the ruler of hell, I think you can figure out what he looks like.